Introduction Lemon basil ( Ocimum × citriodorum Vis.), or maeng-lak in Thai, is a member of the Lamiaceae (Labiatae) family that contains about 65 species of annual and perennial herbs and shrubs indigenous to the tropical and subtropical zones of Asia, Africa and South America. This herbaceous plant is largely cultivated in northeastern Africa and southern Asia and considered to be a natural hybrid between Ocimum basilicum and Ocimum americanum . Besides, it is one of the most economical important spices and medicinal herbs in Ocimum section on account of its strong lemon fragrance used in cuisine, effective essential oils against various pathogens and high antioxidant content and capability [1]-[6]. Report on lemon basil cultured in vitro was really infrequent. So far, there had been only one completed research publication on plantlet regeneration from nodal explants of this species. The highest multiple shoot initiation (15.2 shoots per explant) was occurred when lemon basil node had been placed on Murashige and Skoog (MS) medium containing 1.0 mg/l BA (benzyl adenine) and 0.025 mg/l IAA (indole-3-acetic acid). Then, rooting was successfully obtained on half strength MS medium comprised 0.5 mg/l IBA (indole-3-butyric acid) [7].